Error while transfering ftp + ssl using lftp flient
lftp put: 'Access failed: 521 Data connections must be encrypted'
# Start lftp as below
Shell >>lftp -u user ftp.domain.com -e "set ftp:ssl-protect-data true"
#Transfer file
lftp :~> put -a filepath
Other Usefull links
http://lftp.yar.ru/
Solution By Aliasgar Jiruwala